S-SAFE Study: Protecting Our Subways and Streets

The last study day of the S-SAFE project successfully
concluded on July 25th. The research conducted by the project team will
yield valuable data for air flow models in New York City, information
that will help the City’s first responders to protect New York’s citizens
and visitors, on the streets and in the subway.

If an industrial accident or a terrorist act resulted in the release
of dangerous contaminants into the atmosphere in New York City or in its
subway system, the city’s first responders would have to decide quickly
whether people should shelter in place or be evacuated, and what
evacuation routes should be considered. In July, the New York City
Police Department (NYPD) and the U.S. Department of Energy's Brookhaven
National Laboratory will conduct the country’s largest urban air flow
study to date to better understand the risks posed by airborne
contaminants, including chemical, biological and radiological (CBR)
weapons in the event they are dispersed in the atmosphere and in the
City's subway system. The NYPD will use the data collected during the
three days of research to optimize emergency response following an
intentional or accidental release of hazardous materials. The
Metropolitan Transportation Authority is assisting both agencies with
the study of air flow in the subway system.

The Subway-Surface Air Flow Exchange (S-SAFE), as the project is
formally known, was commissioned by the NYPD and funded through a $3.4
million Department of Homeland Security Transit Security Grant. It is
the first of its scale to study air flow in a dense, complex urban
environment both below and above ground. Researchers from Argonne
National Laboratory and Los Alamos National Laboratory, along with
additional meteorologists and engineers, will support Brookhaven's
scientists as they track the movement of harmless tracer gases detected
by air sampling devices placed in select locations on the street and in
the subway system.

While the study is focused on the air flow and dispersion of airborne
contaminants resulting from the release of a CBR agent, the findings
will also enable City agencies to better understand dispersion
characteristics of other potential inhalational hazards, such as smoke
or fumes from chemical spills. The study is also expected to help police
and other agencies decide where to best locate CBR detection equipment.
Results from the study will help authorities refine evacuation or other
responses in the event of an emergency.

Press Release

Next Study Day

The S-SAFE field study is now completed.

Thursday, July 25, was the third and final study day.

Hoax Literature

Flyers designed to mislead Metropolitan Transportation
Authority (MTA) customers about the Subway-Surface Air Flow
Exchange (S-SAFE) study are being mass produced and posted
at various locations in the subway system, and some have
subsequently been circulated online. This hoax literature
is purposely designed to resemble official agency communications,
and lists false claims about health effects supposedly linked
to the perfluorocarbon tracer gases used in the S-SAFE study.

The perfluorocarbon tracer gases used at very low concentrations
in the S-SAFE study are stable, inert, nonreactive, and nontoxic
even at much higher concentrations. Some acidic, reactive chemicals
in the perfluorocarbon family, including perfluorooctanoic acid
(PFOA) and perfluorooctane sulfonate (PFOS), are thought to be
potentially harmful to human health, are not effective for use as
tracer gases, and ARE NOT being used in the S-SAFE study.

One of ten national laboratories overseen and primarily funded by the Office of Science of the
U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical,
biomedical, and environmental sciences, as well as in energy technologies and national security.
Brookhaven Lab also builds and operates major scientific facilities available to university, industry
and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven
Science Associates, a limited-liability company founded by the Research Foundation for the State
University of New York on behalf of Stony Brook University, the largest academic user of Laboratory
facilities, and Battelle, a nonprofit applied science and technology organization.